Hematology & Hyperbilirubinemia Flashcards

A neonate born to a type O-positive mother is found to be type A-positive and develops jaundice at 18 hours of life. Which condition is the most likely cause?

Answer: ABO incompatibility

ABO incompatibility most commonly occurs when a type O mother carries a type A or B neonate; maternal anti-A IgG antibodies cross the placenta, cause hemolysis, and result in early-onset jaundice.

Which nursing intervention is the highest priority when initiating phototherapy for a neonate with hyperbilirubinemia?

Answer: Apply opaque eye patches securely to protect the retinas

Opaque eye patches must be applied correctly before starting phototherapy to protect the neonate's retinas from damage caused by the high-intensity light source.

How does breastfeeding jaundice differ from breast milk jaundice?

Answer: Breastfeeding jaundice peaks at days 2-4 from inadequate milk intake; breast milk jaundice peaks at days 5-15 from substances in mature breast milk

Breastfeeding jaundice (days 2-4) results from insufficient caloric intake causing dehydration and increased enterohepatic circulation, while breast milk jaundice (days 5-15) is caused by substances in mature breast milk that inhibit hepatic glucuronosyltransferase.

Intravenous immunoglobulin (IVIG) is administered to neonates with hemolytic hyperbilirubinemia to achieve which therapeutic effect?

Answer: Block macrophage Fc receptors to reduce antibody-mediated hemolysis

IVIG occupies Fc receptors on reticuloendothelial macrophages, preventing them from destroying antibody-coated red blood cells and thereby reducing the rate of hemolysis and bilirubin production.

A symptomatic neonate with a venous hematocrit of 72%, jitteriness, and respiratory distress is diagnosed with polycythemia. Which treatment is indicated?

Answer: Partial exchange transfusion using normal saline to dilute the blood

Symptomatic polycythemia is treated with a partial exchange transfusion, removing blood and replacing it with normal saline to reduce the hematocrit to approximately 50-55% and decrease blood viscosity.

G6PD deficiency increases a neonate's risk for severe hyperbilirubinemia primarily through which mechanism?

Answer: Increased hemolysis of red blood cells vulnerable to oxidative stress

G6PD is an enzyme critical for protecting red blood cells from oxidative damage; its deficiency causes hemolysis when cells are exposed to oxidative stressors, increasing bilirubin production.

According to AAP guidelines, when is exchange transfusion indicated for a term neonate with hyperbilirubinemia?

Answer: TSB at or above the exchange transfusion threshold on the Bhutani nomogram, especially with signs of encephalopathy

Exchange transfusion is indicated when TSB meets the exchange threshold on the AAP nomogram based on gestational age and risk factors, or when acute bilirubin encephalopathy is present despite intensive phototherapy.